1. Field of the Invention
The invention relates to component communication systems. More particularly, the invention relates to integrated circuits within component communication systems.
2. Description of the Related Art
Integrated circuit chips and arrangements thereof having the ability to provide inter-component communications at higher speeds and with lower power dissipation has always been a goal for integrated circuit chip and system manufacturers. Integrated circuit transistors are capable of providing a switching performance for high speed data transmission that is greater than the ability of common wire interconnectors to convey such data between integrated circuit chips. For example, the switching performance of metal oxide semiconductor transistors having gatewidths of 1 .mu.m or less produces data for transmission at rates on the order of 1 Gbits/s, which exceeds the capabilities of conventional interconnects such as dual-in-line packages, stitch-bond wires and conventional metal traces on printed circuit boards.
However, certain problems tend to arise when operating at such data transmission rates. For example, at data rates as low as 100 Mbits/s, discontinuities at the interconnect cause a problem of reflecting a portion of a transmitted data signal back to the transmitter integrated circuit. Such signal reflection often destructively combines with the transmitted signal to degrade the signal received by a destination integrated circuit.
Transmission line structures have been employed for interconnects in systems to reduce such discontinuities. In such systems, discrete terminating resistors often are coupled to ends of the transmission line. The terminating resistor has an impedance that matches the characteristic impedance of the transmission line in order to substantially reduce discontinuities and corresponding signal reflections caused by the ends of the transmission line. However, the use of permanent terminating resistors at the ends of the transmission lines causes, inter alia, increased power dissipation.
In conventional communications bus arrangements, i.e., arrangements in which a plurality of integrated circuits or components are coupled to the same signal transmission line or bus, the integrity of transmitted signals often becomes distorted, particularly at their leading and trailing edges despite the use of terminating resistors for the transmission line. Moreover, signals transmitted on the transmission line also suffer from ringing. Such distortion and ringing of data signals often disadvantageously degrade detection and discrimination of the data represented thereby.
Accordingly, there is a need for an integrated circuit communications system and/or method that reduces distortion and ringing of communication signals transmitted along a bus transmission line while also reducing driver power requirements caused by increased power dissipation.